Method of making bags



April 1940- T. E. PIAZZE IIETHOD OF MAKING BAGS Filed Feb. 10, 1938 INVENTOR.

v QM M Patented Apr. 16, 1940 UNITED STATES PATENT OFFICE METHOD OF MAKING BAGS Application February 10, 1938, Serial No. 189,797

6 Claims.

My present invention relates generally to improvements in the art of manufacturing bag-like receptacles, and relates'more specifically to an improved method of making improved bags from sheet material such as thin paper or cellulose film.

Generally defined, an object of my present invention is to provide an improved method of manufacturing durable bags from thin sheet'material.

Bags formed of cellulose film or similar thin and relatively transparent material, have become quite popular for the purpose of merchandizing various commodities in batches. Such bags are ordinarily formed in succession from a continuous ribbon of the film or other stock, which is first folded into longitudinal tubular form with the overlapping edges glued together, and is subsequently cut into desirable lengths and transversely folded and glued at an end of each length or section to produce the final bag. Because of the thinness and texture of the stock used in forming these bags, it is necessary in order to permit convenient spreading of the open bag end, to have the front and rear edges at the open end staggered or off-set. This off-setting of the edges at the ends of the tubular sections combined with the fact that the cellulose film is apt to tear unless properly cut, makes it rather difficult to sever the tubular stock into sections, except by utilizing serrated transverse lip-knives and a striker bar which is adapted to impinge against the tube near the lip-knives and to practically tear the sheet stock off along serrated edges. While such serrated edges are relatively desirable at the extreme outer ends of the completed bags and adjacent to the openings or open ends thereof, they are not desirable along the inner edges of these bag openings since the serrations cause the material to tear quite readily when the bags are being filled. It is therefore very desirable to provide each bag with an open end bounded along one side by a serrated edge and along its opposite side by a. smooth edge, but such bagstructures cannot be'commercially produced in rapid succession, by prior known methods.

It is therefore'a more specific object of my present invention to provide an improved method of producing such improved bags in a most -ef-'-' fective manner and from a continuous ribbon of stock advancing at high speed.

In accordance with my invention, the stock ribbon is longitudinally folded and glued into tubular form as with the prior methods, but I have 1 provided simple and highly efiicient meansfor automatically severing the tube into successive sultant article. a

sections each of which has staggered or ofi-set transverse cuts at least at one end thereof, one of which cuts is serrated while the other is smooth or unserrated. The bags subsequently produced by this method, are superior to the prior bags 5 of the same general type so that my invention involves not only the improved method, but also the improved apparatus for efiecting commercial exploitation of the method, and the improved re- A clear conception of the several steps of my improved method, and of the construction and operation of a machine for carrying on these steps and of the resultant product, may be had by referring to the drawing accompanying and 5 forming a part of this specification, wherein like reference characters designate the same or similar parts in the several views.

Fig. 1 is a somewhat diagrammatic perspective 7 view of one type of apparatus for carrying on 20 my improved method of producing bags, the mechanism for initially folding the stock into tubular form having been omitted;

Fig. 2 is a top view of a part of the apparatus shown in Fig. 1;

Fig. 3 is a longitudinal section through a fragment of the improved apparatus;

Fig. 4 is an enlarged transverse section through the cutting and striker bar; and

Fig. 5 is a plan view of one of the improved 30 bags with a portion of the closed endfolded open.

While I have shown the invention as being applied in the production of bags from cellulose film and each having the outer edge of the open end serrated while the inner edge is straight and 35 smooth, it is not the intent to thereby unnecessarily restrict the scopefsince either edge of the bag opening may be smooth cut and this cut may be curved.

Referring to the drawing, the bag producing 0 machine illustrated therein diagrammatically, comprises in general means 8 providing a support for a.rol1 9 of stock such as thin and relatively transparent cellulose film or paper,which is adapted to be delivered in continuous ribbon form 45 past an adhesive applying roller l0 and over a roller H to a tube former of usual construction (not shown); an adjustable normally stationary elongated former plate. i 2 extending longitudinally within the tube l3 and awayfrom the roller 50 II and tube former; an adjustable support M for the plate, l2 adjustably mounted with respect to a fixed support l5, by means of screws It; a pair of retaining rollers l1 resting upon the upper portion of the tube l3 above the plate l2 somewhat beyond the support M; a former plate reaction roll it coacting with the former plate i2 through the overlapped edges of the tube It beyond the rollers I1; a pair of laterally separated upper driving rollers l9 'coacting through the tube 63 and through side notches or cut-outs in the plate I2, with a lower driving roller 2|, so as to constantly advance the tube 13 along the plate I2; a serrated or toothed lip-knife 22 fixedly positioned above the tube I3 between the driving rollers I3, 2| and a transverse knife edge 23 at the extreme end of the plate I2 within the tube I3; a cutting and striker bar 24 revolvable about the axis of a driving shaft 25, and being swingable upwardly between guides 26 so as to coact sever thetube I3 into successive equal lengths eration with the knife edge- 23.

or sections 21; coacting upper and lower draw rollers 28, 29 respectively, cooperating with the successive bag sections 21 to remove the samefrom the zone of severance; mechanism of well known construction for subsequently folding and gluing one end of each section 21 to complete the bags; and driving mechanism for positively rotating the various feed rollers and for revolving the bar 24 in properly timed relationship.

plate support |4 may obviously be utilized to insure proper cooperation of the cutting blade 23 with the blade 30 01 the cutting and striking bar- 24. The lip-knife 22 should also be so mounted that the off-set between the cut edges 3|, 32 of each bag section 21 may be varied, and the guides 26 are cooperable with the bar 24 and with the blade 30 so as to prevent vibration or chattering thereof and to insure proper cutting coopvW'hile either end of each bag section 21 may be folded over I and attached to complete each bag, it is preferable to fold the bag end as shown in Fig. 5, so that the smooth edge 3| is the inner edge at the bag opening, and is 'the outer edge at the closed end of the bag.

When carrying on my improved method of producing bags with the aid of the apparatus above described, the stock is being continuously delivered from the supply roll 9 past the adhesive applying roller which deposits a continuous strip of adhesive such as glue along one edge of the 1 advancing ribbon. The ribbon is thereafter continuously folded along its longitudinal side portions to superimpose the glued edge over the opposite edge, and to thereby form the advancing collapsed tube I3 embracing and travelling along the fixed plate l2. The rollers I1 function to guide the tube l3 and the reaction roll I8 is set as near as possible to the forming plate I2 so as to prevent this plate from bending upwardly whenever the severing bar strikes the advancing tube I3 and edge 23, while the driving rollers I9, 2| coact with the tube l3 at the notches 23 of the plate I2 and thus constantly iflnaipart advancing motion to the continuous tube The cutting and striker bar as with its blade 33 is being constantly revolved in a clockwise direction as viewed in Fig. 1, and at a uniform rate of speed. As the bar 24 and blade 30 are with the'cutting edge 23 of the plate I2 to produce smooth straight cuts or edges 3| across the under-side of the adjacent portion of the tube I3. At the same time that this smooth cutting is being effected, the bar 24 imparts a blow to the uncut upper portion of the tube and causes the stationary lip-knife to tear or sever the adjacent portions of the tube I3 to produce the serrated edges 32 spaced from the smooth out edges 3|. The extreme side portions of the tube l3 and connecting the corresponding off-set cuts 3|, 32, and which have been previously creased, are torn apart during delivery of the successive blows; and the tube sections 21 which are thus succes-' sively removed from the end of the advancing collapsed tube l3, are subsequently closed at one end to form the completed bags shown in Fig. 5. It will thus be apparent that with my improved process and apparatus, the improved bags with smooth and serrated off-set edges 3|, 32 are quickly and automatically produced.

From the foregoing detailed description it will be obvious that I have provided a simple but effective method of rapidly producing a succession of bags from relatively thin stock such as cellulose film, each of which has a set of staggered or oif-setedges 3|, 32 at each end thereof.

One end of each bag may be subsequently folded and fastenedeither so as to provide an outer serrated or an outer smoothedge at the bag opening; and the provision of the smooth edges at the opposite ends of the bag and the disposition thereof as shown in Fig. 5, will eliminate undesirable tearing during loading of the bags and will also present a neater finish at the closed bag end. My improved process may be conveniently and automatically carried on with the aid of rela tively simple and compact apparatus, and the successive bags may be efiectively produced without noticeably retarding the advancement of the collapsed tube l3. The invention has proven highly successful in actual commercial use and the bags produced by the new method have proven superior to the prior bags of the same general type produced by the previous processes. I

It should be understood that it is not desired to limit this invention to the exact steps of the method or to the precise details of construction of the apparatus, herein shown and described, for various modifications within the scope of the claims, may occur to persons skilled in the art.

I claim:

1. The method of making bags, which comprises, forming a continuously advancing collapsed tube of stock and removing successive sections from an end of the tube by simultaneously transversely shear cutting one layer and impact tearing the other layer along off-set lines of cleavage. i

2.-The method of making bags, which comprises, forming a continuouslyadvancing collapsed tube of stock, and removing successive sections from an end of the tube by simultaneously transversely shear cutting one layer and impact tearing the other layer along off-set lines of cleavage while at the same time. tearing the edge portions of the tube to sever the same between the transverse lines of severance.

3. The method 'of making bags, which comprises, forming an elongated collapsed tube of stock, and removing successive sections of the tube by simultaneously-transversely shear cut ting one layer and impact tearing the adjacent line and the other layer by impact tearing along a serrated line oflf-set with respect to the smooth line 0'! the first mentioned layer while at the same time parting the edge portions of the tube between the cooperating transverse lines of severance.

5. The method oi. making bags, which comprises, forming a longitudinally advancing collapsed tube of stock, and removing successive sections or the tube by transversely severing one layer by draw cutting through the same along a smooth line and the other layer by impact tearing along a serrated line.

6. The method of making bags, which comprises, forming a longitudinally advancing collapsed tube of stock, and removingj successive sections of the tube by transversely severing one layer by draw cutting through the same along a smooth line and the other layer by impact tearing along a serrated line offset with respect to the smooth sheared edge.

' THOMAS E. PIAZZE. 

